Process of carbonizing.



A. F. ROCKWELL.

PROCESS OF OARBONIZING.

APPLICATION FILED JAN.10,,1910.

975,076. Patented Nov. 8, 191 0.

WITN ESSESQ said flask. The gas t STATES rATENT OFFICE.

ALBERT F. ROCKWELL, OE BRISTOL, CONNECTICUT, ASSIGNOR TO THE 'NEW DEPABF'rrnm MANUFACTURING COMPANY, 01 CONNECTICUT.

Speciflcation of Letters Patent. n Application filed IanuarylO, 1910.Serial No. 5s7Q191.

or narsror, connncrrcu'r, A coarona-rron rnocnss'o'r caanonrzmo.

Patented Nov. 8, 1910.

To all whom it my mom:

Be it known that I, ALBERT F. ROCKWELL, a citizen of the United States,residin at Bristol, county of Hartford, State of 0 necticut, haveinvented a certain new and useful Process of Garbonizing, of which thefollowing is a full, clear, and exact description, 'suchas will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanying drawings, forming part ofthis specification.

My invention bonizing.

One object is to so introduce a carbonbearin fluid'into a flask that theintroduction 0 such fluid does not chill the'material to be treatedconfined in such flask.

Another object is toavoid oxidation of the material being treated.

A further object is to provide for evenly distributing the ca' bonthroughout the body of the article being carbonized. i

To these ends, and also to improve generally upon processes of thecharacter indicated, my invention consists in thevarious mattershereinafter described and claimed.

I In carrying out my invention a carbonbearing gas is first brought to aheat as great as that of the material being treated and is at suchtemperature thenintroduced' into contact with the said material. In thisway the incoming gas does not interfere with the carbonizmg operation bychilling the material. Indeed, at the beginning of the operation, thegasis generally at a temperature greater than that of the said material, inwhich event said incoming gas not only does not chill the material butassists in heating thesame.

I prefer to employ a heating chamber separate from ,the flask whichcontains the material to be treated but communicating with said flask,such heating chamber being of a temperature at least equal to (and, asabove explained, "some times greater than) that of the flask, and tointroduce a carbonbearing liquid, such as a hydrocarbon oil, into saidheatin chamber in small quantities, whereby said oil is converted intogas and heated, the heated gas then passing into us creates its ownpressure in the heating chamber whereby relates to processes of car-vsaid gas. is forced into said flask and into intimatecontact with thematerial therein.

Preferabl the air is driven away from the material be ore the latterreaches the degree o f heat which would produce oxidation and air iskept away from said material until the carbonizing process is completed,thus avoiding oxidation and its attendant disadvantages. This ex ulsionof the air is accomplished by permitting a small amount of thecarbon-bearin gas to enter the flask containing the material before thelatter has become sufliciently heated to oxidize, such] supply of gasbeing suflicient to drive oil the air to produce appreciablecarbonization. After the air is thus driven off, the supply of gas iscut off and the gas in the flask lies dormant, thus excluding the air,until the material has been brought to the desired temperature forcarbonization, when the gas is admitted in carbonizing quantity and theprocess of carbonizing commences.

Sometimes it is desirable to distribute the carbon throughout the bodyof the article being treated, rather than to produce a-fin- 'ishedarticle with a relatively high carbon outer portion and .a low carbon orsoft interior. This is advantageous, for example, in carbonizing springplates where it is desired to carbonize the whole body of the article toa relatively small degree and yet is disadvantageous to give the articlean outer portion highly carbonized. When it is de-' sired toproduce anarticle thus evenly carbonized throughout its body, I cut ofi the supplyof carbon-bearing fluid after the article has (at its outerportion)absorbed the total quantity of carbon desired to be distributed throughthe body of the article, but I maintain the article at its carbonizingheat. In this way no additional carbon is supplied but the interior ofthe body. of the article absorbs carbon from the relatively highlycarbonized outer portion, thus'increasing the carbonization of theinterior and correspondingly reducing the degree of carbonization of theouter portion until the whole of the carbon is evenly distributed. Inthis way it is possible to produce, for example, an article of a lowdegree of carbonization but evenly carbonized throughout its body; andby employing the carbon-bearing fluid but insufficient, when initiallysupplied,

I 12, and such oil as the carbonizing agent thewhole operation isperformed without the necessity of reducing the temperature of thearticle be ng treated or of handling the same during treatment.

,The accompanying drawing illustrates an apparatus for use in racticingmy process, Figure 1 being an eevation on about the line 1lof Fig. 2;and Fig. 2. being a view on about the line 2-2 of Fig. 1.

As here illustrated such apparatus embodies a furnace wall 1 providing afire chamber 2 which may be heated by the gas or oil burners 3, aheating chamber 4 within said fire chamber and separated therefrom bythe surroundin wall 5, and a flask 7 in said heating chamber and havingits lower head 10 su ported, as by the standard 11 above the fl dorof'the heating chamber and provided with inlet openings 8 for the heatedas,there being a gas outlet 9 from the flas and the heating chamberhaving a valve-controlled inlet 12 for the hydrocar In racticin theprocess, the material is placed in said ask, the removable cover 6 isput in place to close the heating chamber and the furnace is heated.Preferably, a

small amount of .the hydrocarbon oil is nowintroduced into the heatingchamber 4, the resulting as flowing into the flask 7 and driving ofl theair therein to prevent oxidation as above explained. When the propertemperature has been attained, say a red heat, oil isagain admittedthrough the inlet and heated to the temperature of the heating chamber,which is always as great as the temperature of the material in theflask. The heated gas, of course, creates its own pressure in theheating chamber and is thus forced through the inlets 8 into the flaskand into intimate contact with the material therein, such heated gas notchilling the material as it enters the flask. Indeed,'at the be inningof the operation the tem era: ture 0 the gas is greater than that o thematerial in the flask, so that at the outset the incoming gas not onlydoes not chill the material but such gas assists in heating the same.

When it is desired to distribute the carbon throu hout the body of thearticle as above descri ed, the su ply of oil from the inlet12 is merelycut 0 the flask being continued material to carbonizing is at onceconverted into gasat carbonizing temperature until. the desireddistribution of carbon is effected.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is 1. The process of carbonizing which consistsin heating a carbon-carrying fluid to a temperature greater than that ofthe material being treated, supplying said fluid at such temperature tosaid material until the latter reaches carbonizing temperature, and thencontinuing to supply said fluid to said material at substantlally thecarbonizing temperature of the latter; substantially as described.

2. The process of carbonizing which consists in heating acarbon-carrying fluid to a temperature greater than that of the materialbeing treated, bringing said fluid into contact with said material afterthe fluid is thus heated, and heating said material to carbonizingtemperature; substantially as described.

3. The process of carbonizing which consists in introducing acarbon-bearing liquid in relatively small quantities into a closed andheated chamber whereby said liquid is converted into gas and said gasexerts pressure, permitting said heated gas to flow under such pressureinto a flask communicating with said chamber and containing the materialbeing treated, and heating said temperature; substantially as described.

4. Theprocess of carbonizing which consists in introducing acarbon-bearing liquid in relatively small quantities into a closedchamber which is heated to such a degree that the said liquid isconverted into gas Which exerts pressure and is at a temperature'atleast as great as that of the material being treated, permitting saidgas at said temperature to flow under such pressure into a flaskcommunicating with said chamber and containing the material beingtreated, and heating said material to carbonizing temperature;substantially as described.

In testimony whereof, I hereunto aifix my signature,in the presence oftwo Witnesses.

ALBERT F. ROCKWELL.

Witnesses:

Josnrrr D. BROWN, GEORGE- L. SANFORD.

